Cadillac SRX First Generation Forum - 2004 - 2009 Discussion, 2004 SRX not starting in Cadillac SRX Forums; this is an old thread... but I wanted to add how I finally fixed my problem to help others!!!!
this is an old thread... but I wanted to add how I finally fixed my problem to help others!!!!
After elminating as many things as I could doing my own repairs, I finally felt like the Cadillac dealer had to fix it (car sat in garage for almost a year as I didn't want to concede defeat... haha). The fix was a new ECM. Dealer said that when the key turned and wouldn't start, there was no communication with the ECM. What I think happened is there was a crack in the circuitry in the ECM... and it slowly gets worse... some days it works... some days it don't. I've had other electrical problems like this I've fixed resoldering connectors, etc. I did get a code a few times that said something about ECM Error. But very rarely. Again, I could get it to start by disconnecting negative cable and keep re-attaching. This must have caused enough voltage "spike" to occasionally overcome the ECM circuit issue. Again, I think it was a bad solder joint somewhere in the ECM.
I will recap what I believe are some of the common issues with this no start, key gets stuck condition:
1) bad battery (replaced several times with no help, but it will do this if the voltage is low)
2) bad wiring connections, battery cables, cable at fuse box, etc. (I really thought this was my issue, but I checked and they were all good)
3) bad ignition switch (replaced no help)
4) shifter thinks it's in park (my car always locks and unlocks doors perfectly when I shift from P to D, so I ruled this out)
5) bad crank position sensor (replaced no help, not sure when this is bad if it cranks and won't start or just won't crank?)
6) new ECM (FIXED IT!!!)
as a bonus... my adjustable pedals began working again after the new ECM. I have no clue why??? I did have to reprogram my other key so it worked. This process is rather easy... you just put in the working key turn to ON position (5 secs or so), then put in the non-working key turn to ON position (5 secs or so). Then your other key should be programmed. I'm sure dealer would have done this for free, but saved me a trip.
I asked the dealer if this was a common issue and they said NO. They replace ECM's on vehicles now and then, but not for this reason.
Not to be confrontational but when an ECM is replaced one of the things that happens is all the grounds of the ECM are cleaned and tightened, and lack of ground at the ECM may have been the problem all along. Tough to prove either way, unless they gave you the old ECM.
Where are these grounds anyhow? There are 2 grounds on the battery negative terminal. One is attached to the structure near the front right shock tower, the other one is attached to the rear of the engine. I did check and clean the ground near the shock tower. The one on the engine isn't very accessible, so I checked it with ohmmeter... and we got 12.5 volts across the ground and battery. There is just a cable harness at the ECM... no special grounds I found.
So I really don't think it was a ground issue... but it was odd my power pedals began working again after the fix.
One (or maybe 2) of the ECM mounting bolts are grounds for the ECM case (very important) plus there is a redundant ground strap on the case that goes to another bolt. Plus attaching the harness sometimes improves connectivity on the connector pins.